The present invention relates to a device for the levelling and profiling of railroad ballast beds, the device having at least one lateral plough associated with one rail and designed to operate outside the rail, the plough blade being adjustable in height in relation to the plane of the track, and being also adjustable in width and angularly in relation to the longitudinal axis of the track.
In known devices of this type, various means for attaching the blade of the lateral plough to the chassis of the mobile device have been tried out, with more or less success, for the purpose of obtaining the aforesaid mobility and adjustments. The problem is actually relatively complex because of the considerable resistance to the progress of the plough-blade offered when the said plough-blade is in cantilever in relation to the chassis of the mobile device, and because of the large number of settings required, from the folded inoperative position to the various extended positions used in levelling and profiling the ballast bed.
According to the known most recent means of attachment, the blade of the lateral plough is hinged, by means of a connecting part comprising two hinge axes at right angles to each other, as in a "cardan joint," to an arm moving transversely of the track on a cross slide integral with the chassis of the mobile device, the slide being stationary in relation to the latter.
With this type of attachment, the plough-blade is adjusted angularly in relation to the longitudinal axis of the track by rotating it about the two hinge axes of the connecting part, in horizontal and vertical planes, while width adjustment is effected by displacement of the arm in its slide.
However, since the said slide is stationary in relation to the chassis of the mobile device, adjustment of the height of the plough blade can be carried out only indirectly by rotating the blade in a vertical plane transversely of the track. This is a disadvantage, since the only way of moving the edge of the blade from a given angular position to an angular position parallel therewith is by moving the arm laterally in its slide, which means altering the distance of the sphere of action of the blade from the axis of the track. Moreover, with this type of attachment it is impossible to adjust the height of the plough blade if the prescribed position of the lower edge thereof is parallel with the arm-slide, since in this case transverse movement of the arm moves the edge of the blade only along its line of action.
In another means of adjustment, in which the plough is adapted to move longitudinally in relation to the chassis of the mobile device, it has been suggested that the arm carrying the blade be mounted on a support moving vertically in a vertical slide integral with the said chassis. With this arrangement, however, the arm supporting the plough blade cannot be moved or adjusted transversely of the track, and the required total mobility in all directions is thus not obtained. Furthermore, superimposing two motions of translation obtained by means of systems using vertical and longitudinal guidance slides, at least one of which is in cantilever, results in a design which is heavy, expensive and subject to rapid wear.